更改DB2中的主键序列（＆＃39;默认＆＃39;到＆＃39;始终＆＃39;）

Question

我在DB2中创建了下表。由于序列是GENERATED BY DEFAULT，因此可以将主键插入表中（因为在使用alter创建表之后添加主键）并且可能存在重复值。解决方案是使用GENERATED BY ALWAYS创建序列。现在我在表格中有数据，我想将其从GENERATED BY DEFAULT更改为GENERATED BY ALWAYS

  CREATE TABLE HW_COB.ILCCDS 
  ( 
                   CDS_IDENTITY FOR COLUMN CDSID NUMERIC(13, 0) GENERATED BY DEFAULT AS IDENTITY ( 
                   START WITH 1 INCREMENT BY 1 
                   NO MINVALUE NO MAXVALUE 
                   NO CYCLE NO ORDER 
                   CACHE 20 ) ,

CODE_1 FOR COLUMN CDSCD1 CHAR(30),
CODE_2 FOR COLUMN CDSCD2 CHAR(30) );
ALTER TABLE HW_COB.ILCCDS ADD CONSTRAINT HW_COB.PK_CDS_IDENTITY PRIMARY KEY (CDS_IDENTITY);

Answer 1

  

最后得到了改变：

ALTER TABLE HW_COB.ILCCDS ALTER COLUMN CDS_IDENTITY SET GENERATED ALWAYS;